settingsPage Init selfhost (#4734)

# Description of Changes

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Please provide a summary of the changes, including:

- What was changed
- Why the change was made
- Any challenges encountered

Closes #(issue_number)
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---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

---------

Co-authored-by: James Brunton <[email protected]>

frontend/src/core/components/shared/AppConfigLoader.tsx

@@ -0,0 +1,24 @@
+import { useEffect } from 'react';
+import { useAppConfig } from '@app/contexts/AppConfigContext';
+import { updateSupportedLanguages } from '@app/i18n';
+
+/**
+ * Component that loads app configuration and applies it to the application.
+ * This includes:
+ * - Filtering available languages based on config.languages
+ *
+ * Place this component high in the component tree, after i18n has initialized.
+ */
+export default function AppConfigLoader() {
+  const { config, loading } = useAppConfig();
+
+  useEffect(() => {
+    if (!loading && config) {
+      // Update supported languages if config specifies a language filter
+      updateSupportedLanguages(config.languages);
+    }
+  }, [config, loading]);
+
+  // This component doesn't render anything
+  return null;
+}